Flooring in workplace or storage areas in which oil and water spills commonly occur is often made of a refractory, porous substance such as concrete, stone or brick. Use of such materials is desirable due to their load-bearing capacity and resistance to harsh chemicals but such floors are likewise difficult to clean, being porous and uneven.
Previously, porous minerals such as bentonite and vermiculite have been used to clean up oil and water spills on such surfaces. However, the use of mineral particles which are large enough to be easily removed from the floor results in a relatively small surface area of the particles being available to contact and absorb the spilled oil, while the use of fine particles results in a gummy caked mass which is difficult to remove from the floor surface and dispose of. Also clay and other particulate minerals do not function to remove oil which has become absorbed into the porous floor.
The preparation of open-celled, hydrophilic polyurethane foams by the reaction of specially-formulated prepolymer resins with large excesses of water without the need for added catalysts or cross-linking agents is disclosed in U.S. Pat. Nos. 3,890,254; 4,137,200 and 4,160,076. These resins permitted the introduction of large amounts of solids into the foam matrices via preformed aqueous slurries of solid particles which were subsequently reacted with the prepolymer resin in order to foam it into the desired specialty product.
Such products are disclosed in U.S. Pat. Nos. 3,833,386; 4,066,394; 4,066,578; 4,309,509 and 3,343,910 which describe the incorporation into hydrophilic foams of sinterable ceramic materials, water-softening minerals such as zeolites, flame retardants, odorant-containing waxes and fine abrasives, respectively. The resultant foamed products are produced so as to exhibit satisfactory overall integrity for use in polishing pads, sachets, laundry sponges, cushions and the like.
Desirable qualities in such products include high tensile strength, compressibility and a fine or even cell structure. Although hydrophobic, or petrophilic polyurethane fibers have been disclosed to be useful to absorb oil from oil-water sludges, there has heretofore been no indication that the solids-containing foams prepared as described above would be useful for such purposes, probably due to their strong hydrophilicity.
Therefore, it is an object of the present invention to provide a composition suitable for cleaning concrete flooring which has been soiled by oil spillage, the term "concrete" as used herein to include any hard, porous material such as stone, brick, tile, plaster and the like. The term "oil" as used herein is intended to include any liquid, viscous, nonpolar chemicals, and is not limited to petroleum distillates.
It is a further object of the present invention to provide a solids-containing, open-celled, reticulated hydrophilic foamed product suitable for absorbing oil and/or water spills on concrete surfaces.